Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The immunologic and genetic analysis of a 14-week-old-male cardigan Welsh corgi puppy that presented with failure to thrive, diarrhea, and intermittent vomiting are described. The lack of palpable lymph nodes, the premature death of a male sibling, and similar clinical signs in a male cousin suggested that a primary immunodeficiency disease might be responsible for his poor clinical condition. Quantitation of serum immunoglobulins revealed low concentrations of IgG and undetectable IgA, yet normal concentrations of IgM. A complete blood cell count showed a slight anemia and lymphopenia. Although the peripheral blood contained a normal percentage of T cells, with an increased CD4:CD8 ratio, they were unable to proliferate in response to phytohemagglutinin (PHA) and/or interleukin 2 (IL-2). Furthermore, following PHA activation, the peripheral blood lymphocytes (PBL) demonstrated a nearly complete lack of IL-2 binding. All of these laboratory findings were identical with our previous findings from dogs with X-linked severe combined immunodeficiency (XSCID) that is due to a mutation in their IL-2 receptor gamma (IL-2R gamma) chain. Examination of the corgi's IL-2R gamma cDNA revealed an insertion of a cytosine following nucleotide 582, resulting in a premature stop codon prior to the transmembrane domain. The insertion also created an EcoO109 restriction enzyme site that enabled us to detect the mutation in the patient's genomic DNA. This new mutation in the IL-2R gamma chain discovered in a cardigan Welsh corgi puppy results in XSCID with similar immunologic abnormalities as observed in dogs with the same disease resulting from a different IL-2R gamma chain mutation.
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PMID:A single nucleotide insertion in the canine interleukin-2 receptor gamma chain results in X-linked severe combined immunodeficiency disease. 857 41

Denileukin diftitox, a genetically engineered fusion protein combining the enzymatically active domains of diphtheria toxin and the full-length sequence for interleukin-2 (IL-2), efficiently targets lymphoma cells expressing the high-affinity IL-2 receptor (IL-2R) consisting of the alpha/p55/CD25, beta/p75/CD122, and gamma/p64/CD132 chains. In vitro studies demonstrated that the retinoid X receptor (RXR) retinoid, bexarotene, at biologically relevant concentrations of 10(-6) M to 10(-8) M, upregulated both the p55 and p75 subunits of the IL-2R and enhanced 5- to 10-fold the susceptibility of T-cell leukemia cells to denileukin diftitox. To determine whether this biomodulatory effect could be recapitulated in vivo, we treated 14 patients with relapsed or refractory cutaneous T-cell lymphoma with escalating doses of bexarotene (75 mg/day-300 mg/day) and denileukin diftitox (18 mcg/kg per day x 3 days every 21 days) in a phase 1 trial. Overall response was 67% (4 complete responses, 4 partial responses). Modulation of IL-2R expression was observed at or above a bexarotene dose of 150 mg/day. Four patients experienced grade 2 or 3 leukopenia, and 2 had grade 4 lymphopenia. Our results demonstrate that the combination of denileukin diftitox and bexarotene is well tolerated and that even low doses (150 mg/day) of bexarotene are capable of in vivo upregulation of CD25 expression on circulating leukemia cells.
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PMID:A phase-1 trial of bexarotene and denileukin diftitox in patients with relapsed or refractory cutaneous T-cell lymphoma. 1581 59

X-linked severe combined immunodeficiency is a life-threatening disorder caused by mutations in the gene encoding the interleukin-2 receptor gamma chain (IL2RG). Hypomorphic mutations and reversion of mutations in subpopulations of cells can result in variant clinical phenotypes, making diagnosis and treatment difficult. We describe a 5-year-old boy with mild susceptibility to infection who was investigated for a mutation in IL2RG due to persistent natural killer (NK)- and T-cell lymphopenia. A functionally relevant novel T466C point mutation was found in B, NK, and epithelial cells, whereas alpha/beta and gamma/delta T cells showed the normal gene sequence, suggesting reversion of the mutation in a common T-cell precursor. This genetic correction in T cells resulted in a diverse T-cell repertoire and significant immunity despite failure to produce specific antibodies linked to an intrinsic defect of mutant B cells. These observations confirm the potential of revertant T-cell precursors to reconstitute immune function, but questions remain on the longevity of revertant cells implicating the need for careful follow up and early consideration of hematopoietic stem cell transplantation (HSCT).
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PMID:Clinical and immunologic consequences of a somatic reversion in a patient with X-linked severe combined immunodeficiency. 1872 47